Dyeing or coloring of products made with cellulose acetate



Patented Feb. 22, 1921.

UNlT-EDSTATES PATENT OFFICE.

e'nonon HOLLAND nuts, or sromaon, mean nnnsv nnenann, assienon TO AMERI-CAN CELLULOSE AND CHEMICAL MAN PORATION OF DELAWARE.

DYEINC OB OI PRODUCTS MADE WITH CELLULOSE ACETATE.

No-Drawing. Application filed September 25, 1923, ScrialNo. 684,780, andin Great Britain January 27,

This invention relates to the d eing which term also includes printingan rics, films or other products made of or containing celluloseacetate.

According to the invention, coloring matters or organic compounds whichhave an' employin them in the form-of solubilized,

1. e. solu 1 or more soluble modifications, obtained by pretreating themwith bodies having oily or fatty characteristics, 001111 311119 ing saltformi'ng groups capable of forming soluble salts with alkalies orammonia, for example the sulpho group or the carboxyl group. or bothsnlpho and carboxyl' groups, or, salts of such-bodies, such for instanceas "their sodium or other alkali salts or ammonium salts. Such bodiesand their salts are hereinafter included in the term -.body of oily orfatty char'acteristics- Inparticularone can employ sulphoricinoleic acidor ather sulphonated fatty acidsor salts thereof such as referred'tmbutother bodiesof oily or fatty characteristics may-be employed,

' for dye! such as'folelc, stearic o1" palmitic acid, or salts am orthereofisuch-for instance as the sodi other-alkali salts or ammoniumsalts. Mixitures of two or more than two of any of the aforesaidsolubilizing agents" may be emf-1,

whether or not e simple amino. bases themplplyh dr I I e invention mayespecially be employed cellulose acetate with 'non sul phonated or otherinsoluble orrelatively ina soluble organic compounds orcoloring mattersof tha azo class. It may likewise 'be' employed for dyeing celluloseacetate by the name or development "proces with simple stencilling ofartificial yarns or threads, filaments, fabmatters, or by any othercoloring matters or compounds havin an aflinity for or capable ofcoloring cellu ose acetate, but the use of which by the ordinary methodsis impracticable or difiicult owing to their insolubility or lowsolubility in water, such for example as unreduced coloringmatters ofthe substi t'uted-quinone mono-imide series generally comprisedwithinthe term indophenols; or coloring matters or compounds ofthe followingclasses usually containing no sulpho groups:-diphenylmethane,triphenylmethane, vtriarylmethane, oxazine, azine,

uracrunrne COHPANY LIMITED, a condiazine, thiazine, unreduced indigoid,-orbasic derivatives of the anthraquinone series;

as instances may be mentioned, rosaniline base, alkylate'd or arylatedrosaniline bases, pararosa-nilin'e base,tetra-methyl-dipara-amidotriphenyl carbinol (malachite green base),amido anthraquinones, and amidohydroxy- 'anthraquinones or theirderivatives, such as 1-hydroxyparatolyl-amino-anthraquinone, l-paratolylamino-4-methyl aminoanthraquinone safranine base, and so forth.

With reference to the d eing with the sim ple amino bases (other t an.amino azo coloringmatters) by the azoic or. development process, thatis-to say wherein the actual estufl is produced on the cellulose acetatere or material by the development method j;

of formation with the aid of said bases and.

'a'zoic development, it is understood that the expression organiccompounds capable of co oring cellulose acctaic" emplo ed in the presentdmcription and in the claims applies to the-said simple amino bases-1nthe sensethatth are capable of coloring the cellulose acetate y suchroduction of a dye-thereon,

selves' colour cellulose acetate. It is furtherv .dye' the soubilizedmodifications of the simple amino bases may be employed eitherin the first or-im regnating bath-of the process or 1 in thefinadevelopment? bath or in both amino bases otherlthan' amino azo coloring.baths.

' contain in their molecule, besi es It is known that the aflinities ofacetyl cellulose for various coloring matters are azo, amino, imino,imide, nitro, nitroso, |s0- nitroso, hydroxyl, acidyl-amino, being fa-.vourable. For example, it may be stated that the group -NH and itsalkyl substituents, and the group --N:N are very favourable, the groupsNO and -OH are somewhat favourable, but the group SO,,HY is veryunfavourable to the fixation of the coloring matter by the acetyl cel'lulose material.

The inhibitive influence of the strongly acidic SO H group limits theutility of many of the existing commercial coloring matters,particularly of the azo class, since most of these contain this group,in the absence of which from the molecule the dyestuff would in mostcases be insoluble or of such low solubility in water as to be uselessof practical application. For this reason many coloring matters of theazo class have formerly been synthesized Within the acetyl cellulosematerial by the process of dyeing ,one soluble component upon thematerial, diazotizing the component, and treating the diazo compoundwith a solution of a suitable second component, such as a phenolic oramino body of the benzene or naphthalene series.

It has now been found that the dyeing of cellulose acetate in thread,fabric, film or other form can be effected with any con titutionallysuitable, but insufliciently soluble compounds or coloring matters ofthe -'azo class, if the said compounds or coloring matters are appliedin the form of soluble modifications made by treating them with one ormore of the bodies of oily or fatty characteristics and in particularwith sulphoricinoleic or other sulphonated fatty acids or their salts.

The said compounds or coloring matters of the azo class (which class asis known includes azo compounds whether mono-azo, disazo, trisazo,tetrakisazo and others), while being without strongly acidic groups,such as the SO H group, ma or may .not

the favourable N=N- group, primary or secondary or tertiary aminogroups, such as the alkylated or arylated amino groups, or substituentgroups such as nitro, chlor, ethoxy, methoxy.

Whenthe said azo compounds or coloring matters contain primary aminogroups and are diazotizable, they may be diazotized and developed withinthe acetyl cellulose material by coupling with suitable developers suchasphenolic. or'amino bodiesof the henzene an naphthalene series.

The following are examples of azo compounds and coloring matters whichmay be applied according to the process.

Certain nmino-nzu-bcmcuc suhxlilucnl llr'rirulirrx,

Viz: (a) Nitro- (h) Di-nitro- (0) Methyl nitro- (d) Dimethylnitro- (c)Methoxy- (1) Chlor-methnxy- (y) Nitmmethoxy (h) Ethoxy- (i)ChloM-thoxyl. .'lmino:w.ohenzenr s ll.--Monnmethylamino-azo hemmn-s lll.-l)imethy]amiun am brnzenes lV.-l Inno-cth vlamino azo henzencs V.--I)iethylumino azo henzenes VI.-Ethylniethylamino azo hen'mnrs ll.-llonopheuyluminouzo bcnzeues \lII.lhcnyhncthylamiuo azo benzeneslX.Pheny1ethylnmine am lwnzenes (J) Nltro ethoxy- X.-Aminomonomcthyl ambenzene (k) Chlor-nltro- Xl. -Aminodimcthyl um benzene made bydiazotizing the [(a.) to sllbstituted anilines, and combining with (I)aniline. or with (ll) to (VI) alhylated m dialkylalcd anilincs, or with(VII) arylated aniline or with (VIII) and (1X) alltylaryla'ted anilines,or with mctatolui- (line, or with (Xi) para-xylidine.

2m) Ethoxybcnzene-azo- 'n) Chlor-ethoxy-bcnzene-nzo- (o)Nitro-ethoxy-benzene'azo made by diazotizing [(a) to (0)] aniline or thesubstituted anilines and combining with (I) alphanaphthylanline, or withthe fill to VI) ('5) alkylated or dialkylated alphanaphthylainines, orwith (VII to X) (i) arylated, diarylated or alkylarylalcdalphanaphthylamines, or with (1) (ii) betanaphthylamine, or with the (IIto VI) (i/I) alkylated or dialkylated betanaphthylamines, or with the(VII to X) (ii) arylated, diarylated or alltylarylatedbetanaphthylamines.

llapthal ene-azo-anilincs and certain of their substituent derivatives.

I. IL-Monnmethyl- Viz III.-])nnethyl- I a) Na hthalene1.a1.olb) Chornaphthaleno lzazo- Monoethyl' (c) Nitronaphthalene I zazo- (d)Naphthalene 2Euzo- (e) Chlornnphthulon'e 2:aw-- (I) N itronaphthulcne2:110-

a-lkylarylatbd anilines, of (X) with metatoluidine, or (XI) withpara-xylidine.

Amino-a'zonapfithalenes and certain of their substituent derivatives.

Viz: (a) alpha-amino (b) alpha-monomethylamino- (c) alpha-dimethylamlnor(d) alpha-rucnoethylamino-f (e) alpha-diethyl'amino- (f)elpha-methylethyl amino- (g) alpha-monophenylamino- (Ialpha-diphenylamlno- (I) lp -P 11 melhylaniino' I. Na lithalenes I 1 2;1: 1 e y 3 -azo-{ II. Ch ornaphthal nos beta monomethylgmino III.Nitrouaphtha ones (m) beta-dimethylamino- (n) beta-monoethyl ammo- (0gbeta-diethyl amino- (p beta-methyl-ethyl amino- (q)beta-monophenylaminobeta-dlphenyl amino- (8) beta-phenyl-methylammo- (t)beta-phonyl-ethyl ammomade' by diazotizing 1 1 alpha and betanaphthylamines or (II) '-chlor-alpha and chlor-beta naphthylamines, or(III) nitroalpha and nitrobeta naphthylamines,'-and coupling with [(a)to-(f)] alpha-naphthylamine orthe alkylated or .dialkylated alphanaphthylamine's or With to arylated, diarylated 0r alkylarylated alpha.naphthylamines, or with to (p)] betanaphthylamineor the alkylatedprdialkylated beta naphthylamines, or with [(9) to (25)] arylated,diarylated or alkylarylated' beta naphthylamines.

The following, for instance, are some examples of azo coloring matterwhich may be applied according to the lIlVeIIt10Il1- As before indicatedone can also apply the invention for the dyeing of cellulose acetatematerials b the azoic or development method wit simple amino bases. Suchbases are for example paranitraniline, metanitraniline; benzidine,dianisidine, d'imeth.

alphanaphthylamine and diphenylamine. The solubilized modificationsproduced by treatin such base or bases with the sulphonated' atty acidor salt or other bodies of 'oily or fatty characteristics as referred tomay be used either in the first dyeing or impregnating bath, or

ylaniline, and

in the final developing bath or in both.

baths. The advantages of. this anethod'of d eing' or coloring of thatlevel (1 eing and astness to rubbing is often greatly improved, while inthe dyeing or mixed goods, such as mixtures of cotton and acetylcellulose, the

1 danger of damage to the cotton by the use of mineral acids isobviated. Furthermore certain amino bases which do not form in theordinary way, salts sufliciently soluble or stable to be possible ofeasy application,'

compoun s or' coloring matters having an afiinity for or capable ofdyeing acetyl cellulose may be dissolved in the body or I bodies of oior fatty characteristics and be afterwar s-added to the dye baths.

Some of the coloring mattersor compounds for instance dissolve easilydirect 1n the alkali or ammonium salt of sul horicinoleic or othersulphonated fatty aci others are best dissolved in the free sulphonatedfatty acid. Solution may be effected by simply stirring up the dyestuffwith the acid or salt, heating it necessary. The mass can be afterwardsdiluted with water or ueous alkali, boiled and filtered throu h clotinto the dyebath, which may be aci neutral or alkaline. Dyeing can beconducted in the usual manner.

- ter stics, one may obtain useful pinks and re shades in celluloseacetate yarns or fabrics by treating4-nitro-2-me-thoxybenzenel-azo-diethylaniline with enough oleic acid todissolve it on heating, then pouring the hot oily solution into hotWater containing sufiicient ammonia or soda to neutralize the acid andafterwards filtering the solution into the dye bath'and conducting thedyeing as usual. a

If the compound or coloring matter-applied according to the processcontains free primary amino groups andai's diazotizable, it may bediazotized and developedon the material in the customary manner to forma further d'yestufi or dyestuffs In-the case of simple amino bases to beapplied by the azoic'process, the base. or mixture of bases may besimply made into a paste with a sufiiciency of body orbodies of oily or-fatty characteristics, and heated till solution is complete, waterbeing added to dilute as desired, and the solution, after filterin ifrequired, being added to the dyebath; yeing or developing can then beconducted as usual. j v

It is of course understood that mixtures of different coloring mattersor organic compounds'of the. character hereinbefore re- 7 ferred to maybe applied in the form of modifications solubilized or rendered moresoluble by the solubilizing bodies of oily or fatty characteristics.Also that mixtures of such solubilizing bodies may be employed forsolubilizing any of the compounds or coloring matters to be appliedaccording to the invention. l

()ther coloring matters which are not deleteriously affected by thesulphonated fatty acid-or salt or other body of oil or fattycharacteristics may, when desirer be dyed on to the material togetherwith the coloring matters or compounds of the characterbefore indicated.

The compounds or coloring matters to be applied according to theinvention may'if desired be made into solid solutions or complexes orother concentrated preparations suitable for transport and subsequentdissolving and application, by heating them with the body or bodies ofoily or fatty characteristics such as referred to for example oleic,stearic, palmitic or sulphoricinoleic acid, etc. or their salts eitherby treatment in presence of little or no water, or by treatment inpresence of larger quantit-ies of water with subsequent concentration ordrying. For example the preparations may be made by heating the brganiccompound or compounds or coloring matter or coloring matters with thebody or bodies of oily'or fatty characteristics and neutralizing ormixing while hot, with alkalies or ammonia as such, or in saturated ornearly saturated solutions. Or the coloring matters or compounds may bedissolved direct in the hot alkali salt or ammonium salt of the fatty oroily body, or soap to give a solid solution or complex or concentratedpreparation on cooling, and, where neces sary drying. To .dye the acetylcellulose material the solid solution or complex made vas above may besimply dissolved in hot water, the resultant solution being added towater in a suitable vessel and the dyeing be conducted as usual.

It is understood that the invention also extends to the dyeing of mixedfabrics or materials containing cellulose acetate associated withcotton, silk, wool or other threads or fibres with any of the classes oforganic compounds, coloring matters or simple amido bases hereinreferred to.

In particular it has been found that a large number of organic compoundsof the azo class, in the molecule of which the other substituent groupssuch as the amino, alkylated or arylated amino, nitro, chlor, ethoxy,methoxy, may or may not'be present, but from which the sulpho group SO,H is absent, are capable of dyeing fibres, filaments or yarns of acetylcellulose in preference to those of cotton, wool, silk, orartificialsilks of the so-called cellulose type or unesterfiedcellulose. They may thus be used for the dyeing of mixed yarns, fabricsor mate before' referred to.

goo 5,

rials consisting of acet 1 cellulose and one or more of the latter bres,either in uniform shades or in contrasting colours, since a largenumber, of dyestufis exist which are capable of dyeing wool, silk,cotton or artificial silks of the so-called cellulose type inpreference'to acetyl cellulose. Exam les of compounds or coloringmatters suita le for the acetyl cellulose for this purpose are the azocompounds or coloring matters herein- For their applicationthey-arefmade into soluble modifications by treatment withsulphoricinoleic or other sulphonated fatty acids, or salts of said ids,or with the other bodies offoily or ditty characteristics. as abovereferred to.

way of example, in dyeing mixed a quantity of one or more of the azocompounds or coloring matters, a propriate to the percentage of acetylcellu ose in the mixed material, may be dissolved, in the form of theirsolubilized modifications in the'dyc bath and dyeing be proceeded within the usual manner. Where the several dyestuffs or compounds and therequisite assistants are compatible and will mix together withoutdeleterious effect the suitable coloring matter or coloring matters forthe other fibre or fibresmay be added to the same bath. here this is notpossible these other fibres may be first selectively dyed by theapplication of suitable dyestuifs, and ti}; acetyl cellulose beafterwards dyed selectively as above, or vice versa, a Where the azocompound contains a pr1- mary amino group and is capable of ,ClliLZO-tization, it may on the material ers either prior to or subsequently tothe application of the silk, wool, cotton, or other coloring matter; .orsuch other coloring mat,- ter may also be and development manner aseries of very fast and deep shades may be produced.

The invention may dyeing such mixed materials by the aaoic method, bytreatment with bases, e. g. sunple bases such as paranitranihne,metamtraniline, benzidine, dianisidine or alphanaphthylamine,diazotizing and developing in suitable developing baths; or bv treatmentwith bases such as diamethyl aniline, diethylaniline or diphenyl amineand treatment in suitable-diazo solutions. In

such cases'also, the sulphonated fatty acids or their salts or the ot orbodies of oi? or fatty to characteristics will be employe form solublemodifications of the bases,

whether these are employed in the first or impregnating bath or in thesecond or developing bath or in both baths. The other fibre or fibresassociated with the cellulose acetate may be dyed with other dyes inanknown or suitable way.

capable of diazotizatio'nat the same time. In this.

also be applied for be diazotized and developed. I with any suitabledevelop- Instead of dyeing the mixed oods in uniform-shades or incontrasting co ours the cel lulose acetate portion may e dyed, leavingundyed the other fibre or one or more other fibres associated therewith.

This invention is likewise applicable to the printing or stencilling ofthreads, fab-' ribs, or materials consisting of acetyl cellu'- losealone or associated with other fibres or materials. For this purpose, inapplying the compounds,-.coloring matters or primary amido bases {havingan afiinity for acetyl cellulose, suitable amounts of theirmodifications obtained by treating them with sulphonated fatty acids orother bodies of'oily or fatty characteristics, as above referred to, maybe dissolved in water, thickened with substances such as starch, gums,dextrin, flour and the like, and the pastes thus formed be applied tothe material consisting of or containing acetyl cellulose by printinfrom rollers, blocks, etc., or by stencil ing, the material being thendried. The drying is often suflicient to fix the coloring matter,compound or primary. amido base well enough in other cases the materialmay be subjected to a short treatment with steam or ageing. The printedor stencilled material ma be washed or not as desired, and be finis 'edas may be necessary; or where the compounds, colorin matters or organicbases used are'suitable or'or require diazo- 'tization and development,the printed or stencilled material may be so treated for the productionof a very large varietyof shades. Mixtures of difierent organiccompounds,

' coloring matters or simple amino bases, or

any of them, may of course be applied by printing or stencillingaccording to the invention. 1

g In regard to the class of dyestuffs of the substituted quinonemonoimide' series ineluded within the ter m indophenols, it hasbeenfound that these are very useful for acetyl cellulose, many of themembers'of the class having very good direct aflinity or jdyeing.properties for it and yielding shades, e. g. blues and violets, whichare'not .sg-"easily attainable with simple azo'coloring matters. Theresults, moreover, are often -very resistant to light and soaping.

Generally it will be understood that in dyeing, prmting or stencillin ofmaterials consisting of or containin ce lulose acetate, with thesolubilized mo ifications of anyvof'the or anic compounds, coloringmatters or bases avourably constituted or havih anaflilTlty forcellulose acetate as referre to,

' other dyes may or may not be employed in combination or'association'with them in the same'operation, or in separate operat1ons,

for the production of compound shades on the acetyl. cellulose.

. The practical ap lication of the invention plies, it being understoodthat these are given only as instances and can be varied widely. Ewample1.To. dye an orange shade on 100 kilos of cellulose acetate yarn inthehank. 1 kilo of finely ground pa-ranitrobenzene azo diphenyl amine arewell stirred or ground with '10 litres of sodium salt ofsulphoricinoleic acid (50%); the mixture is heated under an open steampipe and then diluted with boiling water and further boiled. The liquoris then filteredinto a dye bath containing cold, soft water. 100-kilosof the material is introduced and dyeing carried out as usual, thetemperature being raised to or 75 C. as may be necessary to exhaust.Volume of dye bath about 30: 1 calculated on the weight of the acetylcellulose. The hanks are afterwards rinsed and finished and dried asdesired.

Emample 2.To dye a gold shade on 25 kilos of acetyl cellulose knittedfabric.

250 grams of benzene azo naphthalene azo phenol mgm Volume of dyebathabout 30:1 reckoned on the weight of the goods. The fabric is thenwashed off in water and as requisite.

' Example 3.To dye a shade of scarlet on 100 kilos of acetyl celluloseyarn in hank by the" a'zoic process.

finished and dried 1.5 kilos of amino-azoebenzene base are mixed andheated with 15 litres of sodium salt of sulphoricinoleic acid (50%); the

mixture is diluted and boiled as in the prebath containing cold, softwater. e goods are then entered and worked, the temperature being raiseduntil the bath is ex-- .vious examples and filtered into the d ehausted. V Volume of dye bath about 30:1

reckoned on the weight of the goods. The goods are then rinsed andworked for 30 minutes in afresh bath containing hard water in which aredissolved 5 kilos of sodium nitrite (98%) and 17-.5 litres ofhydrochloric acid of 17 .7 B. ,Volumeof bath about 30:1 reckoned-onrtheweight of the goods may be illustrate by the following exam- The goodsare then rinsed and developed in hank.

' ricinoleic acid at 100 2 kilos of rosaniline base are dissolved in 15litres of sodium salt of sulphoricinoleic acid (50%) by stirring andheating. The mass is then diluted with hot water and boiled if required,and is filtered into a dye bath containing soft water at 45 C. Volume ofbath about 30:1 reckoned on the weight of the goods. The goods are thenentered and worked, the temperature being subsequently raised to C.until the desired depth of shade is obtained. The goods are thenremoved, rinsed, and finished and dried as desired.

Example 5.-To dye a blue shade on 25 kilos of acetyl cellulose fabric.

3 kilos of diethyl para amido phenyl 1:4 naphthoquinone nionoimide (33%paste) are well mixed with 15 litres of 50% sodium salt ofsulphoricinoleic acid which has previously been heated to 100 C. Afterabout 10 minutes the mass is diluted with boiling water and the whole isfiltered into the dye machine containing cold, soft water. Volume of dyebath about 30:1 on the weight of the fabric. The fabric is entered andworked as usual, the temperature being raised and dyeing continued untilthe desired depth of shade is produced. The fabric is then removed,rinsed, and dried and finished as desired.

Fla-ample 6.-To dye a bluish red on the acetyl cellulose weft and a blueshade on the cotton warp of a mixed woven fabric weighing 25 kilos andcontaining 50 per cent of each material.

Stir 250 grams of finely powdered 2:4-dinitrobenzene-l-azo-diethylaniline into 5 litres of 50% sodiumsalt ofsulpho- G. for 10 minutes. Dilute with boiling water, boil further, and

filter the whole into the dyeing machine containing cold, soft water.Volume of dye bath about 30:1 reckoned on the weight of the fabric.Enter the goods and work as usual, raising the temperature until thedesired shade is produced on the weft. Rinse the material in fresh warmwater and preare a fresh dye liquor containing 375 grams of chlorazolfast blue 213. Enter the goods into this bath and work as usual, raisingthe temperature until the desired shade of blue is obtained on the warp.Finally rinse, soap if required, and dry and finish as may be requisite.

What I claim and desired to secure by Letters Patent is:

1. In and for the dyeing ofyarns, fabrics and other products comprisincellulose acetate, the employment of re atively Waterinsoluble organiccompounds capab oring cellulose acetate, said organic compounds beinemployed in the form of solubilized mo ifications obtained bypretreating them with a solubilizing agent comprising a body of oily orfatty characteristics.

2. In and for the dyeing of threads, fabrics and other productscomprising cellulose acetate, the employment of relativelywaterinsoluble organic compounds capable of coloring cellulose acetate,said organic compounds bein employed in the form of solubilized moifications obtained by pretreating them with a solubilizing agentcomprising a higher fatty acid compound.

3. In and for the dyeng of yarns, fabrics and other products comprisingcellulose acetate the employment of relativel waterinsoluble organiccompounds capab e of col oring cellulose acetate, pounds bein employedin the form of solubilized mo ifications obtained by pretreating themwith a solubilizing agent comprising a sulphonated higher fatty acidcompound.

4. In and for the dyeing of yarns, fabrics and other products comprisingcellulose acetate, the employment of relativel insoluble organiccompounds capab e of coloring cellulose acetate said organic compoundsbein employed ubilized mo ifications obtained by pretreating them with asolubilizing agent comprising a salt of a higher fatty acid compound.

5. In and forthe dyeing of yarns, fabrics and other products tate theemployment of relativel waterinso uble'organic compounds capab e of coloring cellulose acetate, said organic compounds bein employed in thefo'rm of solubilized mo ifications obtained by pretreating them with asolubilizing a ent comprising a salt of a sulphonated hi er fatt acid.

6. In and for the dyeing o yarns, abrics and other products comprisingcellulose acetate, the employment of relatively watere of colsaidorganic com-.

waterin the form of solcomprising cellulose ace- I ubilized m -tate, theemployment of relativel oring cellu ose acetate said organic compoundsbein employed in the form of solofifications obtained by pretreatingthem with' a solubilizing agent comprising aI sulphonated ricinoleicacid bod n and for the'dyeing of yarns abrics and other productscomprising cell ose acewaterinsoluble organic compounds capab e ofcoloring cellulose acetate, said organic compounds bein employed in theform of solubilized mo lfications obtained by pretreating them with asolubilizing agent compris- 'ing a salt of sulphoricinoleic acid.

8. In and for the dyeing of yarns fabrics tate, ,the employment of reativel waterinsoluble organic compounds capab e of coloring celluloseacetate said organic compoundsbein employed in the form of sol= ubilizedm ifications obtained by pretreating them with a solubilizing agentcomprlsing sodium salt of sulphoricinoleic acid.

9. In and for the dyeing of yarns, fabrics and other products comprisingcellulose acetate the employment of relatively waterinso uble organiccompounds of the azo class capable of coloring cellulose acetate, saidorganic compounds of the azo class being em ployed in the form ofsolubilized modifica- 'tions obtained by pretreating them with asolubilizin agent comprising a body of oily or fatty c aracteristics.

10. In and for the dyeing of yarns fabrics and other products comprisingcellu ose ace- .tate, the employment of relatively waterinsolubleorganic compounds of the azo class capable of coloring celluloseacetate, said organic compounds of the azo class bein em-- ployed in theform of solubilized mo ifications obtained by pretreating them with ,a

v solubilizing agent comprising a higher fatty acid compound.

"11. In and for the dyeing of yarns, fabrics and other productscomprising cellulose acetate, the employment" of relatively waterinsoluble organic compounds of the azo class capable of coloringcellulose acetate, said organic compounds of the azo class beingemployed in the form of solubilized modifications obtained bypretreating them with a solubilizingagent comprising a sulphonatedhigher fatty acid compound.

12. In and for the dyeing of yarns, fabrics and other productscomprising cellulose acetate, the employment of relativelywaterinsoluble organic compounds of the azo class capable of coloringcellulose acetate, said organic compounds of the azo class beingemployed in the form of solubilized modifications obtained bypretreating them with a solubilizing agent comprising a salt of a higherfatty acid com und. 13. In 'and for the' g eing of yarns, fabricsand'other products comprising cellulose acetate, the emplogment ofrelatively waterinsoluble organic ompounds of the azo class capable ofcoloring cellulose acetate, said organic compounds of the azo classbeing employed in the form of solubilized modifications obtained bypretreating them with solubilizing agent comprising a salt of asulphon'ated hi her fatty acid.

.14. In an for thedyeing of yarns, fabrics and other products comprisingcellulose acetate, the employment ofrelatively waterinsoluble organiccompounds of theazo class capable of coloring cellulose acetate, saidorganic compounds of the azo class being employed in the form ofsolubilized modifications obtained by pretreating them with asolubilizing-a ent comprising a sulphonatcd ricinoleic aci body.

15. In and for the dyeing of yarns, fabrics and other productscomprising cellulose acetate, theemployment of relatively waterinsolubleorganic compounds of the azo class capable of coloring celluloseacetate, said organic compounds of the azo class .being employed in theform of solubilized modifications obtained by pretreating them with asolubilizing agent comprising a salt of sulphoricinoleic acid.

16. In and for the dyeing of yarns, fabrics and other productscomprising cellulose acetate, the employment of relatively waterinsoluble organic compounds of the azo class capable of coloringcellulose acetate, said organic compounds of the azo class beingemployed in the form of solubilized modifications obtained bypretreating them with a GEORGE HOLLAND ELLIS.

